1. Field of the Invention
The present invention relates to a device for performing an assay, and more particularly concerns a self-contained reagent package device useful in the performance of chemical and biological assays.
2. Description of the Prior Art
Test devices and procedures for assaying chemical and biological liquids are commonly known and used in laboratory practices. Assays are performed to determine trace amounts of many organic materials including drugs, contaminants, pollutants and the like. Similarly, assays are performed on biological liquids such as serum, urine, cerebrospinal fluid and peritoneal exudates. Different types of assays have been employed depending upon the analyte of interest, and include radioimmunoassays (RIA), enzyme-linked immuno-sorbent assays (ELISA), immunoradiometric assay (IRMA), immunofluorometric assay (IFMA), and other various immunoassays.
Even though assays have been carried out for many years and there are devices which seek to simplify and accurately perform the assays, the need continues for further improvements in assay devices. For example, cross-contamination still remains troublesome, as well as delays for reagent changeover during the assay procedures. Frequent transfer or the pipetting of materials is still involved which could cause inaccuracies of the results. Further, the preparation and pattern of using reagents causes drawbacks in the methodology of the assay procedures, particularly if specific agents are required in non-specialized laboratories.
Various assay devices and procedures have been taught in the prior art. For example, U.S. Pat. No. 3,825,410 describes a disposable combined storage and reaction cell for use in the performance of chemical and biological reactions. This reaction cell is designed to facilitate dispensing the reactants into a container of suitable size and form and the stabilization of the reactants so dispensed. Improvements in storage and transportation under various conditions of temperature and humidity are also described. The patented invention further provides for the addition of sample diluent or other agents and the initiation of the reaction, and finally the separation of the component to be measured from the other components of the reaction.
In U.S. Pat. No. 4,090,850, an apparatus is described for use in radioimmunoassays. Such apparatus includes a receptacle tray with a multiplicity of wells. Each of the wells has at its bottom an orifice sized and shaped to retain the liquids used in the assay under given pressure conditions. The orifice, however, permits the evacuation of liquids therethrough at reduced pressure. This patented invention is said to simplify the manipulative steps that the laboratory technician must use, as well as obviate the need for aspiration of the liquids to be tested.
A test apparatus for the determination of immunoassays of antigens and antibodies is described in U.S. Pat. No. 3,932,141. In that invention, the apparatus includes a receptacle tray with a plurality of wells for receiving samples, and balls coated with an immunologic composition. Use of these coated balls is said to effectuate improvements in reproducibility and exactness in radioimmunoassay techniques.
In U.S. Pat. No. 4,160,803, a self-packaged test kit is described. The self-packaged structure is used as a kit for handling and carrying out tests utilizing collection tubes and fraction columns, including a plurality of modular laboratory racks.
An automatic enzyme immunoassay apparatus is described in U.S. Pat. No. 4,383,041. That apparatus includes a rack for holding test tubes; in the test tubes are beads which provide surfaces for the immunochemical reactions.
Notwithstanding the devices and procedures described in the aforementioned prior art, as well as other known and used assay devices, there is room for further improvement in this area. It is to such improvements that the present invention is directed.